Too many scam coins, and people have grown wary of investing in them.
This is basically what happens.....
1. People invest in scam coins
2. The scammers receive the Eth in exchange for their worthless tokens, and they just want to get rid of the Eth to get real money
3. They are willing to accept well below market-rates as in their minds they will take a hit to get real money out
4. This has a snowball effect as everyone sees the price dropping and they panic sell the eth they hold themselves.
5. Rinse and repeat
The sooner these scam coins can be "purged" the better. Thankfully people are waking up to this, and now do a lot more research and investigation before investing. They want to see full transparency. They want to understand how the tokens work and how the smart contracts behind them work. The industry tends to "self-regulate" over time (a good thing) and we reach a point where investors see an opportunity that is just too good to ignore, and the bull run begins once again.
It's happened before, and it will happen again.....hopefully this time many of the scam coins will be left behind!